BIBLIOGRAPHY 131 



6. How may the waning of the wheatgrass cover be detected in its early 

 stages? 



6. Discuss the forage value of the wheatgrass type. 



7. What are the most characteristic plants of the mixed grass and weed 

 cover? 



8. Compare the grazing value of the mixed grass and weed stage of vege- 

 tation with that of (i) the climax herbaceous stage, (2) the second weed stage, 

 and (3) the first or early weed stage. 



9. Name seven species common to the second weed stage. 



10. Name six species characteristic of the first or early weed stage. 



11. What effect does the continued grazing of sheep have on an area in the 

 first weed stage? 



12. Discuss the effect of the use of a permanent bed groimd on (i) the 

 vegetation and (2) the grazing capacity of the lands adjacent to the bed 

 ground proper. 



13. (a) Are the grazing indicator species the same everywhere? (b) How 

 may they be recognized in different localities? 



BIBLIOGRAPHY 



Chapline, W. R. Production of Goats on Far Western Ranges. U. S. 



Dept. of Agr. Bui. 749, 1919. 

 Clements, Frederic E. Plant Indicators: The Relation of Plant Com- 

 munities to Processes and Practice. Carnegie Institution of Wash., 



Pub. No. 290, 1920. 

 Plant Succession: An Analysis of the Development of Vegetation. 



Carnegie Institution of Wash., Pub. No. 242, 1916. 

 CowLES, Henry C. The Physiographic Ecology of Chicago and Vicinity. 



Bot. Gaz., Vol. 31, Nos. 2 and 3, 1901. 

 Hole, R. S. On Some Indian Forest Grasses and Their Ecology. Indian 



Forest Memoirs, Vol. i, No. i, 191 1. 

 Jardine, James T., and Anderson, Mark. Range Management on the 



National Forests. U. S. Dept. of Agr. Bui. 790, 1919. 

 Moss, C. E. The Fundamental Units of Vegetation. New Phytologist, 



Vol. 9, Nos. I and 2, 1910. 

 Sampson, Arthur W. Herding Hints from the Changing Range. Nat'l 



Wool Grower, Vol. 10, No. 5, May, 1920. 

 Plant Succession in Relation to Range Management. U. S. Dept. of 



Agr. Bui. 791, 1919. 

 Succession as a Factor in Range Management. Jour, of Forestry, Vol. 



15, No. 5, 1917. 

 Warming, Eug. Oecology of Plants. Clarendon Press, Oxford, 1909. 



